Generally, a wind turbine includes a tower, a nacelle mounted on the tower, and a rotor coupled to the nacelle. The rotor generally includes a rotatable hub and a plurality of rotor blades coupled to and extending outwardly from the hub. Each rotor blade may be spaced about the hub so as to facilitate rotating the rotor to enable kinetic energy to be converted into usable mechanical energy, which may then be transmitted to an electric generator disposed within the nacelle for the production of electrical energy. Typically, a gearbox is used to drive the electric generator in response to rotation of the rotor. For instance, the gearbox may be configured to convert a low speed, high torque input provided by the rotor to a high speed, low torque output that may drive the electric generator. More specifically, the gearbox generally includes a gearbox housing containing a plurality of gears (e.g., planetary, ring and/or sun gears) connected via a planetary carrier and bearings for converting the low speed, high torque input of the rotor shaft to a high speed, low torque output for the generator.
Lubrication systems are often used within wind turbines to circulate oil throughout the gearbox, thereby decreasing the friction between the rotating and stationary components of the gearbox as well as providing cooling for such components. In order for lubricant to reach the planetary bearings and/or the gear meshes of the gearbox, the lubricant must be transferred from the stationary gearbox housing to the rotating planetary carrier with minimum leakages.
In a typical wind turbine, however, a sufficient gap is required between the gearbox housing and the planetary carrier to avoid wear in a variety of operational and design conditions (e.g. bearing clearances, component deflections, etc.). Such a gap can allow for significant leakage of any lubricants traveling from the gearbox housing to the planetary carrier.
Accordingly, an improved gearbox lubrication system for a wind turbine that addresses the aforementioned issues would be welcomed in the art.